1. Field of the Invention
This invention relates to reducing moisture in the walls and floors or ceilings of structures which have become wet and more particularly to drying inner layers of sheathing.
2. Description of the Prior Art
At present, a number of wall drying systems have been designed which provide drying air into a wall cavity generally in order to dry out the structural members and sheathing before degradation sets in. An example is U.S. Pat. No. 5,155,924 by Terry C. Smith. This patent describes a blower and hose system for pushing relatively drier room air into the spaces between floor and wall where the drying action of the air circulation then takes place. Holes are cut in the wall or flooring is removed as necessary to provide access, and various diverters are provided to direct the air into the wall cavity.
U.S. Pat. No. 5,408,759 by Lenny Bass shows more flexible devices for diverting the air into the wall cavity. A main extendable chamber has a number of flexible air ducts connected to it for carrying the drying air from the chamber into the wall. Each duct terminates in a piece of PVC pipe which is inserted into a wall access hole. Further U.S. Pat. Nos. 5,419,059 and 5,555,643 show diverting the drying air into the wall through the electrical switch and power outlet boxes found in most walls thereby avoiding or minimizing the number of new access holes that must be opened and later repaired.
A problem in the use of such prior art drying apparatus however is that the moisture may not be in the main wall cavity. Openings for electrical boxes, interior wall access holes or the expansion spaces covered by moldings are in communication with the main wall and floor cavities but may not provide access to the moisture which in some cases is lodged between layers of sheathing and insulation and vapor barriers. A serious moisture problem has been found to exist in some structures using "Exterior Insulation Finish System", (EIFS) in that a crack around a window or other wall opening will admit rain water into the space between the exterior styrofoam insulation and the outer wall sheathing. Since the moisture is on the outside of the sheathing, drying the interior of the wall cavity as shown in the prior art is only minimally effective in preventing sheathing rot and structural damage.